Paperclip: processor proc not firing


It’s extremely rare that I have to post something on the Rails list, but this is one of those times that I’ve been completely stuck for countless hours.

Environment: Rails 2.3.3

I’ve implemented a custom processor proc for video thumbnailing with Paperclip (latest trunk version as git submodule, and yes, it’s updated) using the instructions posted at I’ve updated the interpolations section to reflect the new API, but that’s completely beside the matter.

When I run my rspec test for video, it fails (images are thumbnailed correctly, non-video and non-image files are saved without processing, all as intended):

it “should capture a video frame from video files (mimetyped test)” do

test_file = './spec/models/files/'

mimetype = 'video/quicktime'

doc = =>, mimetype))

lambda {!}.should_not raise_error


I’m mimicking an actual upload to stay as close to the real web interaction as possible.

It bombs with (making the test fail):

identify: no decode delegate for this image format `/var/folders/uQ/uQCnby5GHUOu0O+CzWEVmk+++TI/-Tmp-/stream.6150.4’ @ constitute.c/ReadImage/488.

So for some reason it’s still using ImageMagick to process the attachment, even though I even explicitely set the “video?” instance method to always return true (which should make it fail for normal image files, but even that it doesn’t).

Inspecting the asset brings up the properties I expect to see:

— &id004 !ruby/object:Paperclip::Attachment

_asset_content_type: video/quicktime


_asset_file_size: 2162316

_asset_updated_at: 2009-08-17 15:35:29.113877 +02:00

convert_options: {}

:processors: &id001 !ruby/object:Proc {}

For clarification, my Paperclip method in the model:

has_attached_file :asset,

                :styles => { :full => "1920x1080", :medium => ["205x154", :png], :large => ["450x",:png] },

                :default_style => :full,

                :url => "/uploads/:attachment/:id/:style.:content_type_extension",

                :processors => lambda { |a| ? [ :video_thumbnail ] : [ :thumbnail ] }

I’m completely stumped here, the VideoThumbnail class is never called, even though it’s loaded correctly etc. Been looking and debugging Paperclip itself, hoping to find something in the plugin, but to no avail.

The proc does fire though: when I replace with a.image?, I can see ffmpeg firing for all images in the tests (failing to process them quite obviously).

Just to avoid needless tips on ffmpeg not being correctly installed or anything: I had it working with attachment_fu. The reason I switched to Paperclip is because I hate monkeypatching a plugin (with an extra custom plugin) up to a point where you’re basically making all code ugly and prone to fail as you keep adding extra requirements (it was already getting up to that point). Paperclip just seemed to provide me with nice hooks to do what I want in a beautiful way… if it would work :slight_smile:

Anyone have some genious reason as to why this is happening?

Best regards

Peter De Berdt